It is known that a glomerulal podocyte variously changes in the nephritis crisis. In a congenital nephrotic syndrome patient, for example, it was demonstrated that podocyte nephrin is not expressed, and the importance of podocyte, in particular, that of nephrin has been elucidated in the appearance of albuminurea. Urine sediments contain various components such as ones derived from the kidney, ones contaminated from the urinary tract, and ones precipitated in urine. It is important to examine the kind and amount of urinary sediments for discriminating kidney and urinary tract diseases and knowing their degree. These are usually carried out by the staining followed by the microscopy. It is described that it is useful to observe a podocyte with a microscope in order to detect, as a marker, podocalyxin that is a glycoprotein present on the surface of a kidney podocyte for understanding the condition of nephropathy. (Amer. J. Nephrol. 18, 35-41 (1998)).
However, these assays were carried out by the staining, in particular, the fluorescence-labelled immunostaining using a monoclonal antibody, followed by the microscopy. As tests are carried out by the microscopic examination of each specimen one by one in these methods, procedures were laborious and it was not easy to assay many specimens.
On the other hand, Japan Patent no.2932837 describing a method for assaying human podocalyxin by the enzyme immunoassay or immunoprecipitation only disclosed examples of a method for immunologically assaying human podocalyxin, but did not disclose a method for assaying practical clinical specimens, a result of it, or its clinical utility.